A Response to Terror

Floodgates of Terror

Terrorism and Dams

In
the wake of the tragic attacks of September 11, emergency security
measures were put in place at major dams in the Colorado River system,
but the federal government's initial security plans were flawed.

The Bureau of Reclamation's (BuRec) security measures are weakest
at two of the system's most vulnerable structures, Glen Canyon and
Flaming Gorge Dams. The failure of either could set the stage for a
series of catastrophic events with massive human and economic impacts
extending from Utah to Mexico.

While federal resources are currently focused on protecting the
726-foot Hoover Dam near Las Vegas from terrorist attack, comparatively
little is being done to safeguard Glen Canyon Dam upstream on the
Colorado River or Flaming Gorge Dam upstream on the Green River. After
Hoover, these two dams represent the second- and third-largest dams,
respectively, in the Colorado River Basin.

Dam failure would cause catastrophic damage to the reservoir and
immediate downstream areas. A possible "domino effect" could cause
major damage to the water supply systems of more than 25 million people
in the lower Colorado River Basin, triggering economic disruptions
throughout Nevada, Arizona, California and northwestern Mexico.

While around-the-clock patrols at Hoover prevented boaters from
approaching the dam within a mile upstream and a half-mile downstream,
no such controls were in place at either Glen Canyon or Flaming Gorge.

While trucks and trailers were prohibited from crossing Hoover Dam
and passenger vehicles were subject to search by state highway patrol
officers at checkpoints on either side, truck traffic still moved
freely over the crest of Flaming Gorge Dam and across the Glen Canyon
Dam Bridge. No security checkpoints were erected at either site.

Hoover is by far the best-constructed component of the Colorado
River plumbing system. Anchored into massive granite canyon walls and
designed with enough mass for gravity to hold its reservoir - the
nation's largest - in check, a major attack is unlikely to cause
structural failure. The real problems are further upriver.

The 710-foot Glen Canyon Dam sits tucked into porous Navajo
sandstone that constantly leaks water around the structure. Large
pieces of canyon wall adjacent to the dam routinely break away. BuRec
must install increasingly longer "rock bolts" in an attempt to ensure
stability of the dam's abutment and to protect the dam's powerplant
from falling rock.

In 1983, high water caused portions of the dam's sandstone spillway tunnels to crumble, posing a threat to the abutment.

Any rupture of the dam's crumbling abutments would release two
years' annual flow of the Colorado River to blast its way around the
dam, scouring the Grand Canyon before surging across Lake Mead on its
way to Hoover Dam. In the best-case scenario, this water would flow
over the top of Hoover, creating a downstream flood similar to a Hoover
Dam collapse. At worst, the collapse of Glen Canyon could damage Hoover
Dam, sending four years' annual flow of the Colorado River heading
toward Mexico all at once.

Glen Canyon Dam is an accident waiting to happen. Serious plans
must be put in place for the dam's controlled decommissioning, as the
dam very likely could fail on its own.

A failure at Flaming Gorge Dam, with a full pool of 3.7 million
acre-feet of water, would threaten Glen Canyon Dam downstream.

Below Hoover Dam, where the smaller Davis, Parker and Imperial
dams constitute critical elements of the Colorado River plumbing
system. Damage to the Central Arizona Project Canal, California
Aqueduct and All-American Canal - the region's major water delivery
systems - would jeopardize municipal water supplies from Las Vegas to
San Diego.

Riverside communities in Nevada, California and Arizona as well as
the reservations of the Fort Mojave, Colorado River Indian Tribes,
Chemehuevi, Cocopah and Quechan nations are all at risk in the event of
a major lower-basin flood. Three interstate highways and numerous oil
and gas pipelines cross the river below Laughlin, Nevada.